python/pgq: fixes (event & walker)
sql/pgq: tag pgq.batch_id_seq as dumpable (extension)

That case was broken in old 9.1 releases, fixed since 9.1.7.

The sequence will be owned by extension and without tagging
it will not be dumped in data dump.
londiste.handlers.dispatch: fixed "ignore events aiming at obsolete partitions" bug

but really :-)
debian/changelog: updated
Merge branch 'hotfix/3.1.5.4'